Tick
The minimum price increment a futures contract can move, set by the exchange in its contract specification.
A tick is the smallest allowable price move for a futures contract. Every exchange publishes the tick size in its contract spec; trading in fractions smaller than the tick is not permitted.
Tick sizes vary widely: ES trades in 0.25-point ticks; NQ also in 0.25-point ticks; CL crude oil in $0.01 per barrel ticks; GC gold in $0.10 per troy oz ticks.
Day traders count P&L in ticks before converting to dollars — it keeps the math clean and separates entry quality from contract-size decisions.
On the desk
On a contract with a 0.25 tick and a $12.50 tick value, an 8-tick stop is $100 per contract before fees. That arithmetic belongs in the futures calculator, not in a guess.